Continuous push furnace



W. B. CHAPMAN May 21, l92 9.l

CONTINUOUS PUSH FURNACE 3 Sheets-Sheet l Filed Aug. 2, 1924 May 21, 1929. w. B. CHAPMAN 1,713,995

CONTINUOUS PUSH FURNACE Filed Aug. 2, 1924 3 Sheets-Sheet 2 Z. Z/m//vrofir er MVL Ano/mers May 21, 1929. w. B, CHAPMAN 1,713,995

CONTINUOUS PUSH FURNACE Filed Aug. 2, 1924 3 Sheets-Shea?l 5 l @y y Patented May 21, 1929.

UNITED STATES l 1,113,995 PATENT OFFICE.

WILLIAM B. CHAPMAN, OF JACKSON HEIGHTS, NEW YORK, ASSIGNOR TO THE CHAP- MAN-STEIN FURNACE CO., OF MOUNT VERNON, OHIO, A CORPORATION OF OHIO.

CONTINUOUS PUSH FURNACE.

Application filed August 2, 1924. Serial No. 729,690.

The invention relates to a furnace of the type wherein billets or similar objects to be heated are successively fed into one end of the furnace, and pushed therethrough, until they finally pass out of the furnace at its op osite or delivery end.

ne object of the invention is to provide a furnace of the above nature, of such construction that the flow of the hot gases through the heating chamber may be lcontrolled to produce substantially uniform temperature conditions throughout the width of the heating chamber; in other words, to prevent the formation of localized currents of hot gases at differentk temperatures v from passing through the heating chamber in such a way as to create unbalanced temperature conditions.

Another object is to construct the furnace so with regard to the air and gas which enter into combustion, that the hottest tem peratures will obtain at the point required, namely, near the discharge end of the furnace.

The invention also aims to lead the gases to be burned into the heating chamber in a manner economical from the standpoint of space required, and in such va way as not to interfere with the room needed at the discharge end of the furnace to accommodate the machinery for receiving the billets discharged therefrom.

The invention'also includes certain features of construction to permit proper cleaning of the flues and portways employed in the furnace, and other features of 'construction enabling the billets to be subjected more evenly to the effect of the heated gases.

The above and other objects and features of the invention will be in part obvious and n part more specifically referred to in the description-hereinafter contained, which, taken in conjunction with the accompanying drawings, discloses a preferred embodiment thereof; such embodiment, however, is to be considered as merely illustrative of its principles. In the drawings:

Fig. 1 is a longitudinal vertical sectional view of a furnace constructed in accordance' with the invention.

Figs-2, 3, 4 and 5 are sectional views taken respectively on lines v2r--2, `3-3, 4 4 and 5--5 of Fig. 1, looking in the direction of the arrows.

The invention is illustrated as applied to a furnace having an elongated heating chamber 1, and a suitable door 2 at its entrance end, through which the material to be heated is fed into the furnace. The heated gases pass the chamber 1 from left to right, as the latter appears in Fig. l, and are then led downwardly through ports 3 (Figs. 1 and 2) near the entrance end of the furnace, to a pair of conduits 1 which lead to a suitable recuperator denoted generally by numeral 5, whereby the heat of the spent gases may be utilized -to preheat the 'air for combustion. It will be understood that any suitable apparatus may be employed for the above purpose, but I prefer to employ a recupcrator wherein the spent gases pass back and forth horizontally past courses of hollow tiles, as indicated in Fig. 1, until finallyv they are exhausted through flues 6 at the bottom of the recuperator, The detailed construction of such a recuperator is well known, being shown for example in the United States patent to Stein #1,404,721 dated Jan. 1st, 1922, and accordingly will not be set forth at length herein, it being sutlic-ient for the purposes of the present invention to state that the incoming air passes upwardly through the recuperator 5, through vertical passages in the tiles which make up the recuperator, to a gathering chamber 7 located above the iecuperatr, and thence to a conduit 8 (Figs. 1 and 3) leading toward the delivery end of the furnace.

The billets, ingots or ythe like, to be heated are supported upon water-cooled skids' 9, as they pass through the furnace, the skids being supported near the entrance end ofthe furnace by a plurality of piers 10,` and be-l ing apprbximately horizontal for the major portion of the heating chamber l. At the delivery end of the furnace the skids'9 are downwardly inclined at 11, a discharge slope being provided down which the billets will fall to a vdoorway 12, the door 13 ofwhich will be opened at the proper time to permit the billets to be delivered on to a suitable conveying apparatus, as indicated diagrammatically at the left of Fig. 1 beneath door l? Inaccordance with the'present inventifm the air and gas which enter into combustion,

are led 4into the delivery cud 'of heating chamber 1, through a series of ports space across the width of the furnace,l the object )einer to Amix the air and gas thoroughly at' the start and then int-roducethe mixture into the heating chamber in a manner economical from the standpoint of space occupied, and without necessitating conduits orchambers so located as to interfere with the proper handling of the billets at the discharge end of the furnace.

In the present embodiment of the invention, the gas, (for example producer gas or gasilied oil), is led into the furnace through a plurality of passageways 14 (Figs. 1 and 4) located beneath the incoming air conduit 8, and terminating in a plurality of gas chambers 15 disposed beneath the discharge slope 11 of the furnace. The chambers 15 are preferably provided with suitable cleaning doors 16, to permit the removal of soot, dust and other accumulation therefrom.

The preheated air from conduit 8, passes into an air chamber 17 (see Figs. 1 and 5) located above chambers 15 above described, and provided with a series of vertical hollow walls 18 (see Figs. 3 and 5) providing vertical portways 19 which pass downwardly through the floor 22 of chamber 17 to the various gas passageways 15. Thus in effect the chamber 17 constitutes a mixing chamber for the air and gas, and the walls 18 are preferably provided with caps 20 which are spaced from the upper ends of the walls at certain points to provide laterally directed ports 21, which project the gas transversely into the currents of air passing through portways formed by the space. between the walls 18, and tend to mix the air and gas thoroughly. The combustible mixture of air and gas then rises upwardly between the caps 20 and is ignited in the discharge end of the furnace above discharge slope 11.

The thorough mixing of the air and gas as aforesaid enables the mixture to he quickly` ignited and burned at the discharge slope 11, whereby the ingots pass through the vportion of chamber 17, very little hottest portion of the furnace just before being delivered therefrom, and avoiding any cooling of the ingots which would take place if the mixture of the air and gas were not complete enough to burn until after passing along the heating chamber 1 to some extent. Preferably the gas ports 21 arespaced somewhat from the discharge end walls of the furnace to prevent the flames from overheating the same. f

The floor or bottom wall 22 of the chamber 17 is preferably inclined toward the discharge end of the furnace, providing a chute which leads to a plurality of doorways 23 between the vertical walls 18 above mentioned. Doors 24 permit any scale, dust or other accumulation to be' readily removed through the doorways 23 when desired.

\ Since the4 gas ports 21 are laterally vdirected at their mouths, and located in the upper dust .or scale will accumulate in them, but the major portion of the accumulation will fall to the inclined floor 22 and slide down the latter to the doorways 23.

A pit 25, shown diagrannnatically at the left of Fig. 1, may be employed at the discharge end of the furnace to access to the doors 16 and 24 for cleaning purposes. The billet-conveying apparatus 26 will be supported from a bridge work 27 at the discharge end of the furnace, and extending across the pit 25. The cleaning doors 16 and 24, being located underneath the conveying apparatus, do not encroach upon the room needed for the latter, nor does the conveying apparatus obstruct access to the cleaning doors. The air and gas portways furthermore being entirely contained within the confines of the furnace proper, do not require any extra space either at the discharge end or the sides of the furnace.

After rising from chamber 17, the mixture of air and gas is ignited and passes along the heating chamber 1 over a slag pit 28, which I 'prefer to separate from the discharge end of the furnace by a bridge wall 29, which is substantially lower in elevation than the horizontal portion of skids 9. Such a construction permits the gases of combustion "to pass as well under as over the billets supported by the skids, and thus promotes uniform heating. Furthermore, I lrefer to support the horizontal portions o skids 9 above the slag pit 29 in such a way as to afford free passage of the gases of combustion underneath the skids; as shown, the skids 9 are supported in this part vof the furnace by means of water-cooled pipes 30 passing through the side walls of the furnace, and which afford no such obstruction to the passage of the heated gases underneath the skids as would be entailed for example by supports resting upon the bottom of the'slag pit.

It will be noted that the currents of air and gas mixing in chamber 17, are ignited at a point in the discharge end of the furnace near the doorway 12, with the result that when door 13 is opened, the expanding gases of combustion offset any'tendency toward an inward draft of cold air through the doorway 12.

The air and gas portways, being spaced across. the width of the furnace, project a gaseous current into the heating chamber which naturally fills the entire cross-section of the latter, and in case the hot gases tend to form localized currents of uneven temperatures, the flow of gas or air or both to any particular part of the heatin chamber, may be regulated to restore uniform temperature conditions. For example, either of the gas 4passageways 14 (Fig. 4f) may be regulated to supply more or less gas to its corresponding' chamber 15, by adjustment of suitable -dampers indicated diagrammatically at 31;

permit ready l While a specific embodiment of the invcntion has been disclosed, it will be obvious that many changes may be made therein without vdeparting from its principles, as set forth in the appended claims.

I claim:

1. A continuous push furnace having at,

its discharge end, a seriesof 'alternating upwardly extending gas and air portways opening into the heating chamber of the furnace from underneath, said series of portways being disposed across the widthofthe furnace, certain of said portways being directed laterally at their mouths to deflect their contents laterally into otherportwaysf t,

2. A continuous push furnace having at its discharge end, a series of upwardly extending gas and air portways opening into' the heating chamber of the furnace from underneath, said series of portways being disposed across the width of the furnace, certain of said portways beingformed in upstanding hollow walls extending into a chamber, and said walls being provided with caps which deflect the gaseous currents issuing therefrom laterally into .other portways located in -said chamber between such walls.

3. A continuous push furnace having at its discharge` end a series of upwardly extending air and gas portways opening into the heating chamber of the furnace from underneath, said .series of portways being spacedacro'ss the width of the furnace, a slag pitI associated with the heatingchamber of .the furnace, skid members supported above said slag it and downwardly inclined at the discharge end of the furnace to provide a discharge slope, and a bridge wall for said slag pit extending upwardly to a level substantially below the level of the intermediate portions of the skid members, to permit the heated gases to pass over lsjiid bridge wall and Aunder said skid memers.

4. A continuous push furnace having a plurality of gaseous fuel passageways leading to points spaced across 'the width of the furnace and beneath its' discharge end,

spaced upwardly extending fuel portways communicatingrespectively with said conduits, and upwardly directed air portways disposed between the fuel portways abovementioned adapted to'mix the air and gas beneath the discharge end of the furnace, fand project such mixture into the discharge end of the heating chamber of the furnace fromv underneath, one set of said port-ways being capped and the other set being accessi ble from the end of the furnace for cleaning purposes.

5. A contmuous push furnace having skid members passing through its heating chamber and having at its discharge end av series of upwardly extending gas and air portways opening into the heating chamber of the furnace from underneath, said series of portways being disposed across the width of the furnace and communicating with each other at a point sufficiently beneath the discharge ends of the skid members to mix the gas and air beneath said skid members and cause the mixture to burn substantiallyat the discharge ends of the skid members.

In testimony that I claim the foregoing, I have hereunto set my hand this 11th day of June, 1924.

WILLIAM B. CHAPMAN. 

